Electric condenser.



E. 8. WHEELER & M. SULTZER.

ELECTRIC CONDENSER.

APPUCATION FILED JAN.15,19I6.

Patented Oct. 3, 1916.

UNITED STATES PATENT oEEIoE.

EDMUND B. WHEELER, OF EAST ORANGE BROOKLYN, NEW YORK, ASSIGNORS NEWJERSEY, AND MORTON SULTZER, 015' TO WESTERN ELECTRIC COMPANY, INCOR-PORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELECTRIC CONDENSER.

Specification of Letters Patent. Patented O t. 3 1916 Application filedJanuary 15, 1916, Serial No. 72,228..

To all whom it may concern Be it known that we, EDMUND B. WHEELER andMORTON SULTzER, citizens of the United States, residing at East Orange,in the county of Essex and State of New Jersey, and at Brooklyn, in thecounty of Kings and State of New York, respectively, have inventedcertain new and useful Improvements in Electric Condensers, of which thefollowing is a full, clear, concise, and exact description.

This invention relates to electric condensers, the object being toconstruct a condenser which, during manufacture, can be adjusted to agiven capacity with a high degree of accuracy, and which, during use,will maintain this capacity.

A further object is to construct a condenser on which temperature andhumidity changes shall have as small an effect as possible.

A still further object is to construct a condenser which shall be ruggedand shall be able to stand comparatively rough handling.

Heretofore in condensers of the stack type, it has been customary to usetin-foil as the conducting material between the successive layers ofinsulation. These sheets of tin-foil project at one side or the other,and are brought together to common terminals. In View of the very lowtensile strength of tinfoil, such a terminal is very readily broken,

and great care must be taken in their handiing. In this invention,therefore, we replace part of the tin-foil sheets by some metal ofhigher tensile strength, such as copper or aluminum foil. It is notnecessary that all the sheets shall be of this strong metal, but it isfound that it is suiiicient to have the last few sheets on each side ofthe condenser formed of this stronger metal. These outer sheetsconstitute the main support of the terminals which must be secured tothe condenser. In this invention, also, clamping plates are used forcompressing the sheets of insulating and conducting material to a highdegree, and in a manner which absolutely prevents relative motion of thevarious sheets with respect to each other. It is found furthermore, thatthe use of a few sheets of conducting material of high tensile strengthin these condensers, permits an accurate adjustment of the capacity ofvalue, this adjustment being accomplished by having the capacity alittle larger than is desired for the final value, and then pulling outthe stronger sheets until the desired capacity is obtained. It is foundthat in this manner a very accurate adjustment of capacity can be made.A further final and more accurate adjustment can then be obtained by aslight change in the pressure produced by the clamping plates.

The invention will be better understood by reference to the followingspecification and accompanying drawing, in which- Figure 1 shows across-sectional view of parts of the condenser. Figs. 2, 3 and 4 showthe condenser or parts thereof in perspective and at different stages ofconstruction. Fig. 5 is a perspective view of the condenser oncompletion.

Referring to Fig. 1, there is shown the placed between two clampingplates 15 and 16, which 'plates are then held together by means of bolts20, 21, 22 and 23 which engage with corresponding nuts 25, 26. Forconvenience in mounting these condensers, it has been found desirable tosupply one of the clamping plates with a mounting foot, as shown at 18.Measurements can now be taken of the capacity of the condenser, whichcapacity is known approximately from the number of sheets used, theirarea, and their average distance apart. In general, the number of sheetsis so arranged that the capacity will come out slightly larger than isdesired. By loosening the nuts on the bolts, one or more of the sheets12 may then be pulled out slightly,-and a second measurement can betaken upon the capacity, the process being repeated until the correctvalue is obtained. When this stage of the process of'manufacture hasbeen reached, the tin-foil and copper sheets are cut off within a smalldistance of the mica sheets. The copper is straightened and formed intoa groove, into the bottom of which the tin-foil is pressed, as indicatedin Fig. 3. Into the groove thus formed, there is placed a terminal 30,preferably of copper. The groove is filled with solder and the copperfoil soldered thoroughly to the terminal, in such a manner that acomplete, intimate, metallic contact is established between thetin-foil, copper foil and the terminal. In general when this stage ofthe manufacture has been reached, there will be entrapped in variousparts of the condenser, small quantities of air and moisture, and inorder to insure constancy during use, it is desirable to remove anyexcessive quantity of these elements. Accordingly, the condenser isplaced in a suitable furnace and is maintained at a high temperature toremove any traces of mois-- ture and excessive quantity of air. Afterthis stage of manufacture, a further test of the capacity of thecondenser is made, and in general a small change will be found. Anadjustment can be made for this change 'by means of the bolts holdingthe clamping plates together.

To prevent the entrance of moisture, which would alter the capacity ofthe condenser, ithas been found desirable to seal the whole article withsome material which is impervious to moisture. It has been found that avery suitable material for this, is such a compound as is disclosed inpatent to Pruessman No. 1,127,513, February 9, 1915. The condenser isdipped into a molten mass of such a sealing mixture, and upon cooling afurther measurement is made of its capacity. Again it will be found ingeneral that a slight change in capacity has taken place. This changemay be adjusted for by breaking the seal over the nuts and changingslightly the pressure of the clamping plates. A second immersion of thecondenser into the sealing compound is then made, and it will be foundthat no further changes in capacity take place, and the device standscomplete as shown in Fig. 5.

\Vhat is claimed is:

1. A condenser comprising alternate sheets of insulating and conductingmaterial, the inside sheets of said conducting material being of tinfoiland the outside sheets being of strong metal foil and means for holdingsaid sheets together with a fixed pressure.

2. A condenser comprising alternate sheets of insulating and conductingmaterial, the inside sheets of said conducting material being of tinfoiland the outside sheets being of a strong metal foil adapted to beadjusted in area; clamping plates for said condenser and means foradjusting the ressure of said clamping plates to ad ust t fie capacityof said condenser 3. A condenser comprising alternate sheets ofinsulating and conducting material, the inside sheets of said materialbeing of tinfoil and the outside sheets being of strong metal foiladapted to be adjusted in effective. area; metal clamping plates forpressing said sheets together with a preliminary adjustable pressure,and means for sealing the whole.

4. A condenser comprising alternate sheets of insulating and conductingmaterial, the inside sheets of said conducting material being of tinfoiland the outside sheets being of a metal of high tensile strength; metalclamping plates for pressing said sheets together with a preliminaryadjustable pressure.

5. A condenser comprising alternate sheets of insulating and conductingmaterial, the

inside sheets of said conducting material being of tinfoil and theoutside sheets being of a metal of high tensile strength; iron clampingplates held by screws for pressing said sheets together with apreliminary adjustable pressure.

6. A condenser comprising alternate sheets of insulating and conductingmaterial, the inside sheets of said conducting material being of tinfoiland the outside sheets being of copperfoil; iron clamping plates held byiron screws for pressing said sheets together with an adjustablepressure and an insulating covering sealing the whole.

7 A condenser comprising alternate sheets of mica and conductingmaterial, the inside sheets of said conducting material being oftinfoil, the outside sheets being of copperfoil; the alternate sheets ofconducting material being connected to one terminal and I the othersbeing connected to another terminal, iron clamping plates for pressingsaid sheets together with an adjustable pressure and an insulatingcovering sealing the Whole.

In witness whereof, We hereunto subscribe our names this 14th day ofJanuary A. D.,

EDMUND B. WHEELER. MORTON SULTZER.

